Once you've developed your very own skin-care routine, you'll know you actually have your life somewhat together. It's a threshold to cross into official adulthood, a sign that you've matured beyond the simple soap-and-water style of laissez-faire shower skincare.

Whether you prefer to go the 10-step K-beauty route or like a simple drugstore regimen, everyone's complexion-boosting itinerary is a little bit different. It becomes a little more complicated and a whole lot more disappointing, though, once you notice that you're still breaking out.

Skincare begins from the outside in, including what you're eating and the quality of your diet. If you're facing unexpected or inexplicable breakouts, these nine "healthy" foods may actually be the causes of your acne woes.

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Soy

Soy
Shutterstock

Soy has a reputation for being a great alternative to unhealthy things and it's true that soy has tons of benefits, but it can also wreak havoc on your skin if it's consumed in large amounts or if it comes from unverified sources.

Here's the problem: According to Time, 90% of the world's soy crops are genetically modified or engineered, which is just about as bad for your skin as it sounds. Due to some of its contents, soy can cause hormonal imbalances that lead to acne, redness, and wrinkles, particularly in people who identify as women.

Nuts

As the saying goes, everything should be in moderation. Most diets recommend nuts in large amounts, but if you go overboard on this protein alternative, your skin will pay the price.

A diet rich in omega-3 and omega-6 essential fatty acids is great, but some nuts tend to bring the ratio of omega-6 acids beyond their inflammatory levels. Too many omega-6 acids, which many Western diets rely on heavily for protein, can cause acne and redness. The culprits here are high in omega-6, including walnuts, pine nuts, and almonds.

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Shrimp

Shrimp
Africa Studio/Shutterstock

Another ingredient or compound that can cause zits is iodine. Be on the lookout for foods that contain high levels of iodine, including shrimp and other shellfish. Though these are low in calories, their high levels of the chemical element can cause clogged pores and acne, according to Women's Health.

If you're hoping to maintain a fish-friendly diet, try those with healthy levels of omega fatty acids, including salmon. These won't break you out and they won't break your diet.

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Whole wheat bread

Yes, whole wheat bread is still a much better option than the usual white bread. Sorry to disappoint.

Though modern-day whole wheat is touted as being extremely good for you, its genetic modifications and recent hormonal imbalances aren't ideal for skin, especially for those with sensitivities or allergies. Whole wheat doesn't always mean healthy or even whole grain, so make sure to keep an eye out for foods that contain whole grain ingredients, which are full of vitamin B, a skincare favorite.

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Milk

Dairy is important, giving the body the nutrients it needs for strong bones, but it's also high in testosterone, according to WebMD. Large levels of this hormone can stimulate the glands to produce excess oils, which means an even higher chance of pimples, especially for those with already oily skin.

It's recommended that you keep dairy to a minimum by skipping out on the whole milk or heavy cream and getting calcium from more nutrient-rich sources such as kale and broccoli.

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Agave

Agave
AP Photo/University of Michigan Matthaei Botanical Gardens

Agave sounds like the best all-natural alternative to other sweeteners and sugars, but in reality, it's "90% fructose," according to nutritionist JJ Virgin. Fructose is not only extremely detrimental to the liver, it can cause acne, breakouts, and even eczema, a condition that appears in the form of itchy, dry, flaky skin.

Anyone looking to stay healthy while honoring their sweet tooth and their skin should explore other options. Local honey, raw maple syrup, and other more traditionally-sourced alternatives are much less insidious, according to Fox News.

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Cereal

Breakfast is the most important meal of the day, so make sure it's the best for your body inside and out.

Some cereals may market themselves as being natural, healthy, and completely unrefined, but many are high on the glycemic index, a scale that measures insulin levels and blood sugars. According to Livestrong, the higher a cereal falls on the GI, the higher the chance of it causing pimples and wrinkles.

Be sure that you're checking out the ingredients of your daily breakfast cereal. If you're seeing that it's high on the GI, then try making something at home, whether that's steel-cut oats or quinoa.

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Juice

Juice
Peter Macdiarmid/Getty

Here's a solid piece of advice: read the fine print. In the case of the commonly consumed fruit juices, this knowledge can save your skin from undue stress.

If it's not 100% fruit juice, then it's probably not worth drinking. According to Health, many distributors pump their juices with sugar, which is not only bad for the body on the inside, it can also be a major acne catalyst on the outside.

Try sipping on juices that are made of fruit and only fruit. This will mean saying no to any additional sweetness and saying goodbye to pesky pimples.

Strawberries

Strawberries are delicious. If you're attempting to watch what you eat but you need something sweet, you may instinctively reach for this fruit, but it could be harmful if eaten too frequently.

The problem with strawberries is that they're extremely high in vitamin C, according to Essential Remedies. This is a good thing in terms of skin brightness and longevity, but it can also cause flare-ups, redness, and irritation for certain individuals, particularly in the pesky areas around the nose and mouth.

If you don't want to put down the strawberries, it's always best to snack in moderation. As with all foods, be observant when it comes to how your body and skin react to consumption. Your skin-care routine is worth the added trouble.

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